• brian@programming.dev
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    6 days ago

    things that store it as word size for alignment purposes (most common afaik), things that pack multiple books into one byte (normally only things like bool sequences/structs), etc

    • timhh@programming.dev
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      2 days ago

      things that store it as word size for alignment purposes

      Nope. bools only need to be naturally aligned, so 1 byte.

      If you do

      struct SomeBools {
        bool a;
        bool b;
        bool c;
        bool d;
      };
      

      its 4 bytes.

      • brian@programming.dev
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        2 days ago

        sure, but if you have a single bool in a stack frame it’s probably going to be more than a byte. on the heap definitely more than a byte

        • timhh@programming.dev
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          10 hours ago

          but if you have a single bool in a stack frame it’s probably going to be more than a byte.

          Nope. - if you can’t read RISC-V assembly, look at these lines

                  sb      a5,-17(s0)
          ...
                  sb      a5,-18(s0)
          ...
                  sb      a5,-19(s0)
          ...
          

          That is it storing the bools in single bytes. Also I only used RISC-V because I’m way more familiar with it than x86, but it will do the same thing.

          on the heap definitely more than a byte

          Nope, you can happily malloc(1) and store a bool in it, or malloc(4) and store 4 bools in it. A bool is 1 byte. Consider this a TIL moment.